Organic light-emitting display device and method of manufacturing the same

ABSTRACT

A method of manufacturing an organic light-emitting display device is provided. A plurality of anodes and an auxiliary electrode are formed on a substrate. The auxiliary electrode is separated from the plurality of the anodes. An organic layer is formed on the plurality of the anodes and the auxiliary electrode. An opening is formed in the organic layer by applying a voltage to the auxiliary electrode. The opening exposes the auxiliary electrode. A cathode is formed on the organic layer and the exposed auxiliary electrode. The cathode is electrically connected to the exposed auxiliary electrode.

This application is a divisional of U.S. application Ser. No, 14/224,707filed on Mar. 25, 2014, which claims priority under 35 U.S.C. §119 toKorean Patent Application No. 10-2013-0078420, filed on Jul. 4, 2013 inthe Korean Intellectual Property Office, the disclosure of which isincorporated by reference herein in its entirety.

TECHNICAL FIELD

The present invention relates to an organic light-emitting displaydevice and a method of manufacturing the same.

DISCUSSION OF RELATED ART

Organic light-emitting display devices include a plurality of pixels.Each pixel includes a first electrode, a second electrode, and anorganic layer disposed between the first electrode and the secondelectrode. The organic layer may emit light having a luminance levelcorresponding to an electric current flowing between the first electrodeand the second electrode. The organic light-emitting display devicesdisplay a desired image by controlling the electric current flowingbetween the first electrode and the second electrode.

SUMMARY OF THE INVENTION

According to an exemplary embodiment of the present invention, a methodof manufacturing an organic light-emitting display device is provided. Aplurality of anodes and an auxiliary electrode are formed on asubstrate. The auxiliary electrode is separated from the plurality ofthe anodes. An organic layer is formed on the plurality of the anodesand the auxiliary electrode. An opening is formed in the organic layerby applying a voltage to the auxiliary electrode. The opening exposesthe auxiliary electrode. A cathode is formed on the organic layer andthe exposed auxiliary electrode. The cathode is electrically connectedto the exposed auxiliary electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the present invention will become moreapparent by describing in detail exemplary embodiments thereof withreference to the accompanying drawings of which:

FIG. 1 is a plan view of an organic light-emitting display deviceaccording to an exemplary embodiment of the present invention;

FIG. 2 is a cross-sectional view of the organic light-emitting displaydevice taken along the line II-II′ of FIG. 1;

FIG. 3 is a plan view illustrating the arrangement of a plurality ofanodes and an auxiliary electrode according to an exemplary embodimentof the present invention;

FIG. 4 is an enlarged view of a region IV of FIG. 2;

FIG. 5 is a flowchart illustrating a method of manufacturing an organiclight-emitting display device according to an exemplary embodiment ofthe present invention;

FIG. 6 is a cross-sectional view of the organic light-emitting displaydevice, illustrating an operation of forming a plurality of anodes andan auxiliary electrode according to an exemplary embodiment of thepresent invention;

FIG. 7 is a cross-sectional view of the organic light-emitting displaydevice, illustrating an operation of forming a pixel defining layeraccording to an exemplary embodiment of the present invention;

FIG. 8 is a flowchart illustrating an operation of forming an organiclayer according to an exemplary embodiment of the present invention;

FIG. 9 is a cross-sectional view of the organic light-emitting displaydevice, illustrating an operation of forming a hole injection layer andan operation of forming a hole transport layer according to an exemplaryembodiment of the present invention;

FIG. 10 is a cross-sectional view of the organic light-emitting displaydevice, illustrating an operation of forming organic light-emittinglayers according to an exemplary embodiment of the present invention;

FIG. 11 is a cross-sectional view of the organic light-emitting displaydevice, illustrating an operation of forming an electron transport layerand an operation of forming an electron injection layer according to anexemplary embodiment of the present invention;

FIG. 12 is a cross-sectional view of the organic light-emitting displaydevice, illustrating an operation of forming an opening in the organiclayer according to an exemplary embodiment of the present invention;

FIG. 13 is a plan view illustrating an arrangement of a plurality ofanodes and an auxiliary electrode according to an exemplary embodimentof the present invention;

FIG. 14 is a cross-sectional view of an organic light-emitting displaydevice according to an exemplary embodiment of the present invention;

FIG. 15 is an enlarged view of a region XV of FIG. 14;

FIG. 16 is a cross-sectional view of an organic light-emitting displaydevice according to an exemplary embodiment of the present invention;

FIG. 17 is an enlarged view of a region XVII of FIG. 16; and

FIG. 18 is a flowchart illustrating a method of manufacturing an organiclight-emitting display device according to an exemplary embodiment ofthe present invention,

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Exemplary embodiments of the inventive concept will be described belowin detail with reference to the accompanying drawings. However, theinventive concept may be embodied in different forms and should not beconstrued as limited to the embodiments set forth herein. In thedrawings, the thickness of layers and regions may be exaggerated forclarity. It will also be understood that when an element is referred toas being “on” another element or substrate, it may be directly on theother element or substrate, or intervening layers may also be present.It will also be understood that when an element is referred to as being“coupled to” or “connected to” another element, it may be directlycoupled to or connected to the other element, or intervening elementsmay also he present. Like reference numerals may refer to the likeelements throughout the specification and drawings.

FIG. 1 is a plan view of an organic light-emitting display device 100according to an exemplary embodiment of the present invention.

Referring to PIG, 1, the organic light-emitting display device 100includes a plurality of pixels (P1, P2, P3). Each of the pixels (P1, P2,P3) emits light, and the organic light-emitting display device 100displays an image by controlling the luminance of light emitted fromeach of the pixels (P1, P2, P3). The pixels (P1, P2, P3) are arranged ina matrix pattern, but the arrangement pattern of the pixels (P1, P2, P3)is not limited to the matrix pattern.

The pixels (P1, P2, P3) include first pixels P1, second pixels P2, andthird pixels P3. The first through third pixels P1 through P3 may emitlight of different colors. In an example, the first pixels P1 may emitred light, the second pixels P2 may emit green light, and the thirdpixels P3 may emit blue light. However, the present invention is notlimited thereto. One first pixel P1, one second pixel P2, and one thirdpixel P3 which are adjacent to each other may collectively function as aunit for displaying an image on the organic light-emitting displaydevice 100.

The organic light-emitting display device 100 will now be described inmore detail with reference to FIG. 2, FIG. 2 is a cross-sectional viewof the organic /light-emitting display device 100 taken along the lineII-II′ of FIG. 1.

Referring to FIG. 2, the organic light-emitting display device 100includes a substrate 10, a plurality of anodes (A1, A2, A3), anauxiliary electrode CB, an organic layer 70, and a cathode C.

The substrate 10 is plate-shaped and supports other structures formedthereon. The substrate 10 may be formed of an insulating material suchas, but is not limited to, glass, polyethylene terephthalate (PET),polycarbonate (PC), polyethersulfone (PES), polyimide (PI) orpolymethylmethacrylate (PMMA). The substrate 10 may include a flexiblematerial.

The anodes (A1, A2, A3) are formed on the substrate 10. Each of theanodes (A1, A2, A3) is connected to a thin-film transistor T which willbe described later, and an electric current flowing through the organiclayer 70 is controlled by a signal transmitted from the thin-filmtransistor T. The anodes (A1, A2, A3) may be reflective. For example,the anodes (A1, A2, A3) may be formed of materials including, but arenot limited to silver (Ag)/indium tin oxide (ITO), ITO/Ag/ITO,molybdenum (Mo)/ITO, aluminum (Al)/ITO, or titanium (Ti)/ITO. The anodes(A1, A2, A3) reflect light generated from the organic layer 70 in anupward direction.

The anodes (A1, A2, A3) include a first anode A1, a second anode A2, anda third anode A1 The first anode A1 is disposed in each of the firstpixels P1, the second anode A2 is disposed in each of the second pixelsP2, and the third anode A3 is disposed in each of the third pixels P3.

The auxiliary electrode CB is disposed on the substrate 10 and isseparated from the anodes (A1, A2, A3). The auxiliary electrode CB isformed of substantially the same material as the anodes (A1, A2, A3).For example, the auxiliary electrode CB and the anodes (A1, A2, A3) maybe simultaneously formed of substantially the same material by in thesame process. However, the present invention is not limited thereto. Theauxiliary electrode CB may be electrically connected to the cathode C.

The auxiliary electrode CB may be formed of a material with lowerresistivity than the cathode C. The auxiliary electrode CB iselectrically connected to the cathode C thereby reducing a voltage dropof a voltage applied to the cathode C due to the internal resistance ofthe cathode C.

The anodes (A1, A2, A3) and the auxiliary electrode CB will now bedescribed in more detail with reference to FIG. 3, FIG. 3 is a plan viewof the organic light-emitting display device 100, illustrating anarrangement of the anodes (A1, A2, A3) and the auxiliary electrode CBaccording to an exemplary embodiment of the present invention.

Referring to FIG. 3, the arrangement of the anodes (A1, A2, A3) issubstantially the same as the arrangement of the pixels (P1, P2, P3).The first anode A1 is disposed in the first pixel P1. The second anodeA2 is disposed in the second pixel P2. The third anode A3 is disposed inthe third pixel P3.

The auxiliary electrode CB is arranged in a meshed structure. One firstanode A1, one second anode A2 and one third anode A3 are disposed insidea space surrounded by the auxiliary electrode CB. The auxiliaryelectrode CB is disposed between two neighboring anodes (A1, A2, A3).However, the present invention is not limited thereto, and the shape ofthe auxiliary electrode CB may vary.

The auxiliary electrode GB includes a plurality of end portions CBE. Theend portions CBE are disposed in a non-display area NDA. The endportions CBE are regions of the auxiliary electrode CB which extend tothe non-display area NDA. The organic light-emitting display device 100includes a display area. DA which displays an image and the non-displayarea NDA which surrounds the display area DA. The pixels (P1, P2, P3)and a plurality of pixel electrodes (Le., the anodes (A1, A2, A3)) arearranged in the display area DA, and the non-display area NDA maysurround the outside of the display area DA.

To form the opening OP in the organic layer 70, a voltage may be appliedbetween two end portions CBE disposed adjacent to both sides of thedisplay area DA. To apply a voltage to the end portions CBE, a pixeldefining layer 60 which will be described later need not be formed onthe end portions CBE.

The end portions CBE may be pad portions (CBP1, CBP2) formed byincreasing a width of the auxiliary electrode CB. All of the endportions CBE may be the pad portions (CBP1, CBP2). However, the presentinvention is not limited thereto, and only some of the end portions CBEmay be the pad portions (CBP1, CBP2). Since the pad portions (CBP CBP2)are formed by increasing the width of the auxiliary electrode CB, avoltage may be applied to the auxiliary electrode CB by applying thevoltage to the pad portions (CBP1, CBP2). The pad portions (GBP1, CBP2)include a first pad portion CBP1 and a second pad portion CBP2 which arethrilled at different end portions CBE. The display area DA is disposedbetween the first pad portion CBP1 and the second pad portion CBP2. Anelectric potential is applied between the first pad portion CBP1 and thesecond pad portion CBP2, and thus an electric current flows evenlythrough all regions of the auxiliary electrode CB. Accordingly, heat maybe generated evenly from the auxiliary electrode CB, thereby forming aplurality of openings OP. Each opening OP may have substantially thesame size as other openings.

Referring to FIG. 2, the organic layer 70 is interposed between theanodes (A1, A2, A3) and the cathode C. The organic layer 70 emits lighthaving a luminance level corresponding to an electric current flowingbetween the anodes (A1, A2, A3) and the cathode C.

The auxiliary electrode CB is disposed in the opening OP where theorganic layer 70 does not exist on the substrate 10. The auxiliaryelectrode CB and the cathode C is electrically connected to each other.The opening OP will be described in more detail later with reference toFIG. 4.

The organic layer 70 includes a hole injection layer 71, a holetransport layer 72, an electron transport layer 73, an electroninjection layer 74, and organic light-emitting layers (75 a, 75 b, 75c).

When an electric field is applied between the anodes (A1, A2, A3) andthe cathode C, electrons are supplied from the cathode C to the organiclight-emitting layers (75 a, 75 b, 75 c) and holes are supplied from theanodes (A1, A2, A3) to the organic light-emitting layers (75 a, 75 b, 7c 5).

For example, the holes supplied from the anodes (A1, A2, A3) areinjected into the hole injection layer 71 disposed on the anodes (A1,A2, A3). The injected holes are transported to the organiclight-emitting layers (75 a, 75 b, 75 c) through the hole transportlayer 72. The hole transport layer 72 is disposed on the hole injectionlayer 71.

The electrons supplied from the cathode C are injected into the electroninjection layer 74. The injected electrons are transported to theorganic light-emitting layers (75 a, 75 b, 75 c) through the electrontransport layer 730 The electron injection layer 74 is disposed on theelectron transport layer 73. The organic light-emitting layers (75 a, 75b, 75 c) are interposed between the electron transport layer 73 and thehole transport layer 72.The hole injection layer 71, the hole transportlayer 72, the electron transport layer 73 and the electron injectionlayer 74 may be formed on the display area DA of the organiclight-emitting display device 100. Such layers 71 to 74 need not besubject to a patterning process using a mask. Alternatively, such layers71 to 74 may be patterned using a mask.

The organic layer 70 is not limited to have such four layers 71 to 74.For example, at least one layer of the hole injection layer 71, the holetransport layer 72, the electron transport layer 73 and the electroninjection layer 74 may be omitted from the organic layer 70. The organiclayer 70 may include only one layer among the hole injection layer 71,the hole transport layer 72, the electron transport layer 73, and theelectron injection layer 74.

The organic light-emitting layers (75 a, 75 b, 75 c) are disposedbetween the hole transport layer 72 and the electron transport layer 73.Each of the organic light-emitting layers (75 a, 75 b, 75 c) emits lighthaving a luminance level corresponding to the magnitude of an electriccurrent flowing therethrough in response to an electric field appliedbetween the anodes (A1, A2, A3) and the cathode C. The organiclight-emitting layers (75 a, 75 b, 75 c) may emit light corresponding tothe energy generated by a change in an energy level of excitons formedby the combination of holes and electrons. The organic light-emittinglayers (75 a, 75 b, 75 c are formed on the anodes (A1, A2, A3) by adeposition or printing method using a mask. The organic light-emittinglayers (75 a, 75 b, 75 c) are not he exposed through the opening OP.Therefore, the organic light-emitting layers (75 a, 75 b, 75 c) need notcontact the cathode C through the opening OP. The organic light-emittinglayers (75 a, 75 b, 75 c) include a first organic light-emitting layer75 a, a second organic light-emitting layer 75 b, and a third organiclight-emitting layer 75 c. The first organic light-emitting layer 75 ais disposed on the first anode A1 and may emit red light. The secondorganic light-emitting layer 75 b is disposed on the second anode A2 andmay emit green light. The third organic light-emitting layer 75 c isdisposed on the third anode A3 and may emit blue light.

The opening OP will now be described in more detail with reference toFIG. 4, FIG. 4 is an enlarged view of a region IV of FIG. 2. Referringto FIG. 4, a width d1 of the opening OP at a top surface of the organiclayer 70 is smaller than a width d2 of the opening OP at a bottomsurface of the organic layer 70. To form the opening OP, a voltage isapplied to the auxiliary electrode CB. The auxiliary electrode CBgenerates heat corresponding to the applied voltage, and the heatevaporates the organic layer 70 thereby the opening OP being formed onthe auxiliary electrode CB. The heat is transferred through the organiclayer 70. The organic layer 70 has a temperature distribution where thetemperature is decreased from the auxiliary electrode CB to a topsurface of the organic layer 70. Accordingly, the width d1 of theopening OP at the top surface of the organic layer 70 is smaller thanthe width d2 of the opening OP at the bottom surface of the organiclayer 70 which is closer to the auxiliary electrode CB than the topsurface of the organic layer 70.

Referring to FIG. 2, the cathode C is disposed on the organic layer 70.The cathode C is connected to the auxiliary electrode CB in the openingOP. The cathode C is formed on the display area DA of the organic light-emitting display device 100 without using a mask. The cathode C may beformed of an optically transparent or semi-transparent conductivematerial including, but is not limited to, indium tin oxide (ITO),indium zinc oxide (IZO), a compound of magnesium (Mg) and Ag, a compoundof calcium (Ca) and Ag, or a compound of lithium (Li) and A1. Lightgenerated from the organic layer 70 is emitted to the outside of theorganic light-emitting display device 100 through the cathode C. Toincrease light transmittance of the cathode C, the cathode C may beformed thin. For example, the cathode C may have a thickness of 200 Å orless.

The cathode C may have relatively high resistance to an extent that thecathode C corresponding to each pixel (P1, P2, P3) may have a differentvoltage. For example, when a voltage is applied to the cathode, thevoltage suffers from a voltage drop due to the resistance of the cathodeC. Accordingly, each pixel may have a different cathode voltage. Suchvoltage difference may cause luminance stains on the organic lightemitting display device 100. The auxiliary electrode CB has a lowerresistance than the cathode C, and thus the combined resistance of thecathode C and the auxiliary electrode CB may reduce a voltage drop ofthe cathode C.

The organic light-emitting display device 100 further includes a bufferlayer 20, a semiconductor layer SM, a gate insulating layer 30, a gateelectrode 0, an interlayer insulating film 30, a source electrode S, adrain electrode D, a planarization layer 50, and the pixel defininglayer 60.

The buffer layer 20 is formed on a top surface of the substrate 10. Thebuffer layer 20 may prevent the penetration of impurity elements andplanarize the top surface of the substrate 10. The buffer layer 20 maybe formed of various materials that may perform the above functions. Forexample, the buffer layer 20 may include, but is not limited to, asilicon nitride (SiN_(x)) layer, a silicon oxide (SiO₂) layer, or asilicon oxynitride (SiO_(x)N_(y)) layer. Alternatively, the buffer layer20 may be omitted.

The semiconductor layer SM is formed on the buffer layer 20. Thesemiconductor layer SM may include an amorphous silicon layer or apolycrystalline silicon layer. The semiconductor layer SM may include achannel region, a source region and a drain region. The source region isdisposed on one side of the channel region, and the drain region isdisposed on the other side of the channel region. The source region maybe electrically connected to the source electrode 5, and the drainregion may be electrically connected to the drain electrode D. Thesource and drain regions may be highly doped with P-type impurities suchas B₂H₆. The kind of impurities used to dope the semiconductor layer SMmay be different according to exemplary embodiments.

Alternatively, the organic light emitting display device 100 may includean oxide semiconductor layer in place of the semiconductor layer SM. Thegate insulating layer 30 is formed on the semiconductor layer SM. Thegate insulating layer 30 may insulate the gate electrode G from thesemiconductor layer SM. The gate insulating layer 30 may be formed ofSiN_(x) or SiO₂.

The gate electrode G is disposed on the gate insulating layer 30. Thegate electrode G overlaps at least a region of the semiconductor layerSM. A voltage applied to the gate electrode G may control thesemiconductor layer SM to become conductive or non-conductive. Forexample, a relatively high voltage applied to the gate electrode G maycontrol the semiconductor layer SM to become conductive, therebyelectrically connecting the drain electrode D and the source electrode Sto each other. A relatively low voltage applied to the gate electrode Umay control the semiconductor layer SM to become non-conductive, therebyinsulating the drain electrode D and the source electrode S from eachother.

The interlayer insulating film 40 is formed on the gate electrode G. Theinterlayer insulating film 40 covers the gate electrode G to insulatethe gate electrode G from the source electrode S and the drain electrodeD. The interlayer insulating film 40 may be formed of SiN_(x) or SiO₂.

The source electrode S and the drain electrode D are disposed on theinterlayer insulating film 40. The source electrode S and the drainelectrode D penetrate the interlayer insulating film 40 and the gateinsulating layer 30 to contact the source region S and the drain regionD, respectively. The source electrode S, the drain electrode D, the gateelectrode G, and the semiconductor layer SM may form the thin-filmtransistor T. The thin-film transistor T may determine whether todeliver a signal, which is transmitted to the source electrode S to thedrain electrode D according to a voltage applied to the gate electrodeG.

The planarization layer 50 is disposed on the thin-film transistor T andthe interlayer insulating film 40. To increase the light emissionefficiency of the organic layer 70 disposed on the planarization layer50, a top surface of the planarization layer 50 is flat without a step.The planarization layer 50 may be formed of an insulating materialincluding, but is not limited to, polyacrylates resin, epoxy resin,phenolic resin, polyamides resin, polyimides resin, unsaturatedpolyesters resin, poly phenylenethers resin, poly phenylenesulfidesresin, or benzocyclobutene (BCB). A contact hole H is formed in theplanarization layer 50 to expose a top surface of the drain electrode Dof the thin-film transistor T which will be described later. The cathodeC and the drain electrode D is electrically connected to each otherthrough the contact hole H.

The pixel defining layer 60 is disposed on the planarization layer 50.The pixel defining layer 60 partially covers the anodes (A1, A2, A3) toexpose top surfaces of the anodes (A1, A2, A3). Regions respectivelyincluding the pixel electrodes (i.e., the anodes (A1, A2, A3)) uncoveredby the pixel defining layer 60 and the organic layer 70 and the cathodeC disposed on the pixel electrodes (i.e., the anodes (A1, A2, A3)) maybe defined as the pixels (P1, P2, P3). The pixel defining layer 60covers the auxiliary electrode CB. The opening OP penetrates the pixeldefining layer 60 to expose the auxiliary electrode CB.

Referring to FIG. 4, the width d2 of the opening OP at the top surfaceof the pixel defining layer 60 is smaller than a width d3 of the openingOP at a bottom surface of the pixel defining layer 60. When the voltageis applied to the auxiliary electrode CB, the pixel defining layer 60 isalso evaporated due to the heat generated from the auxiliary electrodeCB. The organic layer 70 and the pixel defining layer 60 have atemperature distribution where the temperature is decreased from theauxiliary electrode CB to the top surface of the organic layer 70.Accordingly, the width d2 of the opening OP at the top surface of thepixel defining layer 60 is smaller than the width d3 of the opening OPat the bottom surface of the pixel defining layer 60 which is closer tothe auxiliary electrode CB than the top surface of the pixel defininglayer 60.

The width d1 of the opening OP at the top surface of the organic layer70 is smaller than the width d2 of the opening OP at the bottom surfaceof the organic layer 70. When the voltage is applied to the auxiliaryelectrode CB, the organic layer 70 may be evaporated due to the heatgenerated from the auxiliary electrode CB. The organic layer 70 and thepixel defining layer 60 have the temperature distribution where thetemperature is decreased from the auxiliary electrode GB to the topsurface of the organic layer 70. Accordingly, the width d1 of theopening OP at the top surface of the organic layer 70 is smaller thanthe width d2 of the opening OP at the bottom surface of the organiclayer 70 which is closer to the auxiliary electrode CB than the topsurface of the organic layer 70.

A method of manufacturing the organic light-minting display device 100will now be described with reference to FIG. 5. FIG. 5 is a flowchartillustrating a method of manufacturing an organic light-emitting displaydevice according to an exemplary embodiment of the present invention.

Referring to FIG. 5, the method of manufacturing the organiclight-emitting display device 100 includes forming a plurality of anodes(A1, A2, A3) and an auxiliary electrode CB (operation S10), forming apixel defining layer 60 (operation S20), forming an organic layer 70(operation S30), forming an opening OP (operation S40), and forming acathode C (operation S50).

The forming of the anodes (A1, A2, A3) and the auxiliary electrode CB(operation S10) will now be described with reference to FIG. 6, FIG. 6is a cross-sectional view of the organic light-emitting display device100, illustrating the forming of the anodes (A1, A2, A3) and theauxiliary electrode CB (operation S10) according to an exemplaryembodiment of the present invention. Referring to FIG. 6, the anodes(A1, A2, A3) and the auxiliary electrode CB are formed on a substrate 10in operation S10. A buffer layer 20, a gate insulating layer 30, aninterlayer insulating film 40, a planarization layer 50, a semiconductorlayer SM, a gate electrode G, a source electrode S and a drain electrodeD are formed on the substrate 10, and the anodes (A1, A2, A3) and theauxiliary electrode CB are formed on the planarization layer 50. Theanodes (A1, A2, A3) are separated from each other. The drain electrode Dis connected to its corresponding anode (A1, A2, A3) through a contacthole H formed in the planarization layer 50. The auxiliary electrode CBis separated from the anodes (A1, A2, A3). The auxiliary electrode CBand the anodes (A1, A2, A3) may be formed of substantially the samematerial. The auxiliary electrode CB and the anodes (A1, A2, A3) may besimultaneously formed using a deposition process using the same mask.

The forming of the pixel defining layer 60 (operation S20) will now bedescribed with reference to FIG. 7. FIG. 7 is a cross-sectional view ofthe organic light-emitting display device 100, illustrating the formingof the pixel defining layer 60 (operation S20) according to an exemplaryembodiment of the present invention. The pixel defining layer 60 isformed on the substrate 10 and the planarization layer 50. The pixeldefining layer 60 partially covers the anodes (A1, A2, A3), but thepresent invention is not limited thereto. The pixel defining layer 60partially exposes top surfaces of the anodes (A1, A2, A3). The pixeldefining layer 60 covers the auxiliary electrode CR The pixel defininglayer 60 need not be formed in a non-display area NDA. The pixeldefining layer 60 need not be formed on end portions CBE of theauxiliary electrode CB which are disposed in the non-display area NDA.

The forming of the organic layer 70 (operation S30) will now bedescribed with reference to FIGS. 8 through 11.

FIG. 8 is a flowchart illustrating the forming of the organic layer 70(operation S30) according to an exemplary embodiment of the presentinvention. Referring to FIG. 8, the forming of the organic layer 70(operation S30) includes forming a hole injection layer 71 (operationS31), forming a hole transport layer 72 (operation S32), forming organiclight-emitting layers (75 a, 75 b, 75 c) (operation S33), forming anelectron transport layer 73 (operation 34), and forming an electroninjection layer 74 (operation S35).

The forming of the hole injection layer 71. (operation S31) and theforming of the hole transport layer 72 (operation S32) will now bedescribed with reference to FIG. 9, FIG. 9 is a cross-sectional view ofthe organic light-emitting display device 100, illustrating the formingof the hole injection layer 71 (operation S31) and the forming of thehole transport layer 72 (operation S32) according to an exemplaryembodiment of the present invention. Referring to FIG. 9, in the formingof the hole injection layer 71 (operation S31), the hole injection layer71 is formed on the anodes (A1, A2, A3), the pixel defining layer 60,and the auxiliary electrode CB. The hole injection layer 71 may beformed on the display area DA without using a mask. The hole injectionlayer 71 need not be formed in the non-display area NDA. The holeinjection layer 71 need not be formed on the end portions CBE of theauxiliary electrode CB which are disposed in the non-display area NDA.

In the forming of the hole transport layer 72 (operation S32), the holetransport layer 72 is formed on the hole injection layer 71. The holetransport layer 72 is formed on the display area DA without using amask. The hole transport layer 72 need not be formed in the non-displayarea NDA. The hole transport layer 72 need not be formed on the endportions CBE of the auxiliary electrode CB which are disposed in thenon-display area NDA.

The forming of the organic light-emitting layers (75 a, 75 b, 75 c)(operation S33) will now be described with reference to FIG. 10. FIG. 10is a cross-sectional view of the organic light-emitting display device100, illustrating the forming of the organic light-emitting layers (75a, 75 b, 75 c) according to an exemplary embodiment of the presentinvention. Referring to FIG. 10, in the forming of the organiclight-emitting layers (75 a, 75 b, 75 c) (operation S33), first throughthird organic light-emitting layers 75 a through 75 c may be formed onfirst through third anodes A1 through A3 and the hole transport layer72, respectively. Each of the first through third organic light-emittinglayers 75 a through 75 c may be formed using an inkjet printing methodor a deposition method using a mask.

The forming of the electron transport layer 73 (operation S34) and theforming of the electron injection layer 74 (operation S35) will now bedescribed with reference to FIG. 11, FIG. 11 is a cross-sectional viewof the organic light-emitting display device 100, illustrating theforming of the electron transport layer 73 (operation S34) and theforming of the electron injection layer 74 (operation S35) according toan exemplary embodiment of the present invention. Referring to FIG. 11,in the forming of the electron transport layer 73 (operation S34), theelectron transport layer 73 is formed on the hole transport layer 72 andthe organic light-emitting layers (75 a, 75 b, 75 c). The electrontransport layer 73 is formed on the display area DA without using amask. The electron transport layer 73 need not be formed in thenon-display area NDA. The electron transport layer 73 need not be formedon the end portions CBE of the auxiliary electrode CB which are disposedin the non-display area NDA.

In the forming of the electron injection layer 74 (operation S35), theelectron injection layer 74 is formed on the electron transport layer73. The electron injection layer 74 is formed on the display area DAwithout using a mask. The electron injection layer 74 need not be formedin the non-display area NDA. The electron injection layer 74 need not beformed on the end portions CBE of the auxiliary electrode CB which aredisposed in the non-display area NDA.

If the hole injection layer 71, the hole transport layer 72, theelectron transport layer 73 or the electron injection layer 74 isomitted from the organic light-emitting display device 100, theoperation of forming the omitted layer need not be performed.

The forming of the opening OP (operation S40) will now be described withreference to FIG. 12, FIG. 12 is a cross-sectional view of the organiclight-emitting display device 100, illustrating the forming of theopening OP in the organic layer 70 (operation S40) according to anexemplary embodiment of the present invention. Referring to FIG. 12, inthe forming of the opening OP (operation S40), a voltage may be appliedto the auxiliary electrode CB, and heat generated from the auxiliaryelectrode CB by the voltage applied to the auxiliary electrode CB maycause a portion of the pixel defining layer 60 and a portion of theorganic layer 70 which are adjacent to the auxiliary electrode CB toevaporate, thereby forming the opening OP. The voltage applied to theauxiliary electrode CB may be high enough to generate heat thatevaporates the pixel defining layer 60 and the organic layer 70. Thevoltage applied to the auxiliary electrode CB may be, for example,15,000 V or higher. The voltage may be applied to the auxiliaryelectrode CB by applying different electric potentials to two endportions CBE of the auxiliary electrode CB. The two end portions CBE maybe in the non-display areas NDA facing each other. If an electricpotential is applied between the two end portions CBE disposed in thenon-display areas NDA facing each other, an electric current may flowevenly through all regions of the auxiliary electrode CR Accordingly,heat may be generated evenly from the auxiliary electrode CB, therebyforming a plurality of openings OR Each opening OP has substantially thesame size with other openings. An electric potential may also be appliedbetween two pad portions (CBP1, CBP2) (that is, two end portions CBE ofanother type) which are wide and thus may be contacted using a tool forapplying electric potentials.

In the method of manufacturing the organic light-emitting display device100 according to an exemplary embodiment, the opening OP where thecathode C is connected to the auxiliaty electrode CB may be formed byapplying a voltage to the auxiliary electrode CB. Therefore, the openingOP may be formed through the hole injection layer 71, the hole transportlayer 72, the electron transport layer 73, and the electron injectionlayer 74 without using an etching process. Accordingly, the method ofmanufacturing the organic light-emitting display device 100 according toan exemplary embodiment does not require the use of a mask in formingthe hole injection layer 71, the hole transport layer 72, the electrontransport layer 73 or the electron injection layer 74 nor in forming theopening OP using an etching process. This may simplify the process ofmanufacturing an organic light-emitting display device according to anexemplary embodiment.

In the forming of the cathode C (operation S50), the cathode C is formedon the organic layer 70. The cathode C is electrically connected to theauxiliary electrode CB in the opening OP. The cathode C may be formed onthe display area DA without using a mask. The forming of the cathode C(operation S50) may produce the organic light-emitting display device100 of FIG. 2.

An exemplary embodiment of the present invention will now be describedwith reference to FIG. 13, FIG. 13 is a plan view illustrating thearrangement of a plurality of anodes (A1, A2, A3) and an auxiliaryelectrode CB according to an exemplary embodiment of the presentinvention. The auxiliary electrode CB may be formed of stripe patterns.The auxiliary electrode CB may include a plurality of straight lineswhich are separated from each other. End portions CBE of the auxiliaryelectrode CB may be, but are not limited to, pad portions (CBP1, CBP2).If the auxiliary electrode CB is formed as a plurality of stripepatterns, a voltage may be applied to each of the stripe patterns toform an opening OP in the forming of the opening OP (operation S40).

An exemplary embodiment of the present invention will now be describedwith reference to FIGS. 14 and 15. FIG. 14 is a cross-sectional view ofan organic light-emitting display device 101 according to an exemplaryembodiment of the present invention. FIG. 15 is an enlarged view of aregion XV of FIG. 14. A plan view of the organic light-emitting displaydevice 101 according to an exemplary embodiment is substantially thesame as that of FIG. 1, and FIG. 14 is a cross-sectional view takenalong substantially the same line as the line II-II′ of FIG. 1.

Referring to FIG. 14, the organic light-emitting display device 101includes a white organic light-emitting layer 76 as an organic layer.The white organic light-emitting layer 76 emits white light at aluminance level corresponding to an electric current flowingtherethrough. The white organic light-emitting layer 76 may containmaterials that emit red light, blue light and green light, respectively.An opening OP is formed in the white organic light-emitting layer 76 anda pixel defining layer 60, and an auxiliary electrode CB is exposedthrough the opening OR The opening OP will now be described in moredetail with reference to FIG. 15.

Referring to FIG. 15, a width d4 of the opening OP at a top surface ofthe white organic light-emitting layer 76 is smaller than a width d5 ofthe opening OP at a bottom surface of the white organic light-emittinglayer 76. When the opening OP is formed in the white organiclight-emitting layer 76 by applying a voltage to the auxiliary electrodeCB, the white organic light-emitting layer 76 is evaporated by heatgenerated from the auxiliary electrode CD. The white organiclight-emitting layer 76 has a temperature distribution where thetemperature is decreased from the auxiliary electrode CB to a topsurface of the white organic light-emitting layer 70. Accordingly, thewidth d4 of the opening OP at the top surface of the white organiclight-emitting layer 76 is smaller than the width d5 of the opening OPat the bottom surface of the white organic light-emitting layer 76 whichis closer to the auxiliary electrode CB than the top surface of thewhite organic light-emitting layer 76.

Referring to FIG. 14, the organic light-emitting display device 101further includes a color filter layer 80. The color filter layer 80 isdisposed on a cathode C. The color filter layer 80 includes a firstcolor filter 81, a second color filter 82 and a third color filter 83 ofdifferent colors. The first color filter 81 is disposed on a first pixelelectrode (i.e., a first anode A1.), the second color filter 82 isdisposed on a second pixel electrode (i.e., a second anode A2), and thethird color filter 83 is disposed on a third pixel electrode (i.e., athird anode A3). The first color filter 81 may be, but is not limitedto, a red color filter, the second color filter 82 may be, but is notlimited to, a green color filter, and the third color filter 83 may be,but is not limited to, a blue color filter,

An exemplary embodiment of the present invention will now be describedwith reference to FIGS. 16 through 18. FIG. 16 is a cross-sectional viewof an organic light-emitting display device 102 according to anexemplary embodiment of the present invention. FIG. 17 is an enlargedview of a region XVII of FIG. 16. FIG. 18 is a flowchart illustratingthe forming of an organic layer according to an exemplary embodiment ofthe present invention. A plan view of the organic light-emitting displaydevice 102 according to an exemplary embodiment is substantially thesame as that of FIG. 1 and FIG. 16 is a cross-sectional view taken alongsubstantially the same line as the line II-II′ of FIG. 1.

Referring to FIG. 16, the organic light-emitting display device 102includes a first organic light-emitting layer 77 a, a second organiclight-emitting layer 77 b, and a third organic light-emitting layer 77 cas an organic layer. The first through third organic light-emittinglayers 77 a through 77 c may emit light of different colors. Forexample, the first organic light-emitting layer 77 a may emit red light,the second organic light-emitting layer 77 b may emit green light, andthe third organic light-emitting layer 77 c may emit blue light.However, the present invention is not limited thereto. The first organiclight-emitting layer 77 a is disposed on a first anode A1, and thesecond organic light-emitting layer 77 b is disposed on a second anodeA2. The third organic light-emitting layer 77 c is disposed on the firstthrough third anodes A1 through A3. For example, the first organiclight-emitting layer 77 a and the third organic light-emitting layer 77c are disposed on the first anode A1, and the second organiclight-emitting layer 77 b and the third organic light-emitting layer 77c are disposed on the second anode A2. Since regions of the thirdorganic light-emitting layer 77 c which are disposed on the first anodeA 1 and the second anode A2 do not emit light, the colors of lightemitted from a first pixel P1 and a second pixel P2 are not affectedfrom the third organic light-emitting layer 77 c.

An opening OP is formed in the third organic light-emitting layer 77 cand a pixel defining layer 60. An auxiliary electrode CB is exposedthrough the opening OP, and the auxiliary electrode CB is electricallyconnected to a cathode C. The opening OP will now be described in moredetail with reference to FIG. 17. Referring to FIG. 17, a width d6 ofthe opening OP at a top surface of the third organic light-emittinglayer 77 c is smaller than a width d7 of the opening OP at a bottomsurface of the third organic light-emitting layer 77 c. When the openingOP is formed in the third organic light-emitting layer 77 c by applyinga voltage to the auxiliary electrode CB, the third organiclight-emitting layer 77 c is evaporated by heat generated from theauxiliary electrode CB. The organic layers 77 a to 77 c have atemperature distribution where the temperature is decreased from theauxiliary electrode CB to a top surface of the third organiclight-emitting layer 77 c. Accordingly, the width d6 of the opening OPat the top surface of the third organic light-emitting layer 77 c issmaller than the width d7 of the opening OP at the bottom surface of thethird organic light-emitting layer 77 c which is closer to the auxiliaryelectrode CB than the top surface of the third organic light-emittinglayer 77 c.

A method of forming the organic layer of the organic light-emittingdisplay device 102 will now be described with reference to FIG. 18.Referring to FIG. 18, the forming of the organic layer (operation S30)includes forming the first organic light-emitting layer 77 a and thesecond organic light-emitting layer 77 b (operation S36) and forming thethird organic light-emitting layer 77 c (operation S37).

In the forming of the first organic light-emitting layer 77 a and thesecond organic light-emitting layer 77 b (operation S36), the firstorganic light-emitting layer 77 a is formed on the first anode A1, andthe second organic light-emitting layer 77 b is formed on the secondanode A2 using an inkjet printing method or a deposition method using amask.

In the forming of the third organic light-emitting layer 77 c (operationS37), the third organic light-emitting layer 77 c is formed on a displayarea DA without using a mask.

Alternatively, the first and second organic light-emitting layers 77 aand 77 b may be formed on the third organic light-emitting layer 77 c.In this case, the forming of the third organic light-emitting layer 77 c(operation S37) may be performed before the forming of the first organiclight-emitting layer 77 a and the second organic light-emitting layer 77b (operation S36).

According to an exemplary embodiment, the process of manufacturing anorganic light-emitting display device may be simplified without using amask for forming organic layer and/or an opening in the organic layer inaddition, an auxiliary electrode may reduce a voltage drop due tointernal resistance of a cathode.

While the present inventive concept has been shown and described withreference to exemplary embodiments thereof, it will be apparent to thoseof ordinary skill in the art that various changes in form and detail maybe made therein without departing from the spirit and scope of theinventive concept as defined by the following claims.

What is claimed is:
 1. A method of manufacturing an organiclight-emitting display device, the method comprising: forming aplurality of anodes and an auxiliary electrode on a substrate, theauxiliary electrode being separated from the plurality of anodes;forming an organic layer on the plurality of anodes and the auxiliaryelectrode; forming an opening in the organic layer by applying a voltageto the auxiliary electrode, wherein the opening exposes the auxiliaryelectrode; and forming a cathode on the organic layer and the exposedauxiliary electrode, wherein the cathode is electrically connected tothe exposed auxiliary electrode.
 2. The method of claim 1, wherein theauxiliary electrode comprises a plurality of a pair of end portionsdisposed in a non-display area surrounding a display area in which theplurality of anodes is disposed and, wherein the voltage is appliedbetween two end portions of each pair of the end portions, and whereinthe display area is disposed between the two end portions.
 3. The methodof claim 2, wherein the organic layer is not formed on the end portions.4. The method of claim 2, further comprising, before the forming of theorganic layer, forming a pixel defining layer, wherein the pixeldefining layer partially covers the plurality of anode, exposing a topsurface of each of the plurality of anodes, and wherein the pixeldefining layer covers the auxiliary electrode.
 5. The method of claim 4,wherein the pixel defining layer is not formed on the end portions. 6.The method of claim 4, wherein the opening penetrates the organic layerand the pixel defining layer to expose the auxiliary electrode.